They can already stand, walk, wriggle under obstacles, and change colors. Now researchers are adding a new skill to the soft robot arsenal: jumping.
Using small explosions produced by a mix of methane and oxygen, researchers at Harvard have designed a soft robot that can leap as much as a foot in the air. That ability to jump could one day prove critical in allowing the robots to avoid obstacles during search and rescue operations. The research is described in a Feb. 6 paper in the international edition of Angewandte Chemie.
"Initially, our soft robot systems used pneumatic pressure to actuate," said Robert Shepherd, first author of the paper, former postdoctoral researcher in the Whitesides Research Group at Harvard, and now an assistant professor at Cornell. "While that system worked, it was rather slow — it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot's jump at 4 meters per second."
Just as with other soft robots, the three-legged jumping system begins life as a mold created by a 3-D printer. The robots are molded using soft silicone that allows them to stretch and flex.
But where pneumatic robots are connected to tubing that pumps air, the jumping robots are connected to tubes that deliver a precisely controlled mix of methane and oxygen. Using high-voltage wires embedded in each leg of the robot, researchers deliver a spark to ignite the gases, causing a small explosion that sends the robot into the air.
Among the key design innovations that allowed the combustion system to work, Shepherd said, was the incorporation of a simple valve into each leg of the robot.
"We flow fuel and oxygen into the channels, and ignite it," Shepherd said. "The heat expands the gas, causing the flap to close, pressurizing the channel and causing it to actuate. As the gas cools, the flap opens and we push the exhaust out by flowing more gas in. So we don't need to use complex valve systems, all because we chose to mold a soft flap into the robot from the beginning."
While the notion of using combustion to power a soft robot was enticing, it also came with a number of critical questions, not the least of which was whether the soft silicone used to create the robots would even survive.
"It's a lot more powerful, but the question we had to answer was whether it was compatible — were the temperatures compatible — with this system," Shepherd said. "What we were able to show is, because the duration of the explosion is so short, the energies absorbed by the robot are small enough to be compatible with soft robots. What's more, the temperature of the robot increases by, on average, less than one kelvin."
While he hopes to see internal combustion systems developed that can allow robots to walk or even run, Shepherd said jumping made sense as a starting point."Because it releases so much energy so fast, it made sense for jumping to be the first 'gait' we explored with this system," he said. "The next step now is to learn how we can use this combustion system for other gaits, like running or even walking."
Other authors on the paper are Adam Stokes, Jacob Freake, Phillip Snyder, Aaron Mazzeo, Ludovico Cademartiri, Stephen A. Morin, George M. Whitesides, the Woodford L. and Ann A. Flowers University Professor at Harvard, and Jabulani Barber, an FAS research associate with the Whitesides Research Group.
Peter Reuell | EurekAlert!
Siemens helps transform the main wastewater treatment plant in Vienna into a green power plant
27.11.2015 | Siemens AG
Stanford technology makes metal wires on solar cells nearly invisible to light
26.11.2015 | Stanford University
Wissenschaftler aus Tübingen und Houston haben zahlreiche neue Zelltypen im Gehirn identifiziert. Im Neocortex von erwachsenen Mäusen führten sie erstmals eine...
Ende der 1980er Jahre erlebte die Erde eine dramatische Klimaveränderung. Sie umfasste die Tiefen der Ozeane ebenso wie die obere Atmosphäre und reichte vom Nord- bis zum Südpol. Ausgelöst durch den Ausbruch des Vulkans El Chichón in Mexico 1982 und verstärkt durch menschliches Handeln folgte daraus die größte Temperaturverschiebung der letzten 1.000 Jahre. Erstmals nachgewiesen hat dies ein internationales Forscherteam um Prof. Philip C. Reid von der Plymouth University und der Sir Alister Hardy Foundation for Ocean Science (UK). Die Ergebnisse wurden kürzlich in der Fachzeitschrift „Global Change Biology“ veröffentlicht.
Abrupte Klimaveränderungen haben oft dramatische Folgen für unseren Planeten. Dennoch sind sie in ihrer Art, ihrem Ausmaß und in ihrer Wirkungsweise meist nur...
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
Fraunhofer ISE demonstriert neue Zell- und Modultechnologien an der Außenfassade eines Laborgebäudes
Das Fraunhofer-Institut für Solare Energiesysteme ISE hat die Außenfassade eines seiner Laborgebäude mit 70 Photovoltaik-Modulen ausgerüstet. Die Module...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
27.11.2015 | Veranstaltungen
27.11.2015 | Veranstaltungen
26.11.2015 | Veranstaltungen
27.11.2015 | Förderungen Preise
27.11.2015 | Unternehmensmeldung
27.11.2015 | Energie und Elektrotechnik